To determine the relative contribution at increased bradykinin levels and decreased angiotensin II levels to renal hemogynamic effects of ACE Inhibitors in African Americans and Caucasians. African Americans develop ESRD at a 4-fold higher rate than Caucasians. The magnitude of the problem and the recognition that the renin-angiotensin-system plays a critical role in the progression of renal disease have provided the rationale for testing the hypothesis that VCEIs are renoprotective in humans. Recruitment of additional hypertensive subjects will be beneficial since our pilot has shown that ACE activity is increased in African Americans as well as the frequency of the ACE deletion allele.